• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.424-432
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• 2007

Biodiesel is gaining more attractive due to its eco-friendly and the fact that it is prepared from renewable sources. It is monoalkyl esters of long chain fatty acids derived from vegetable oils and animal fats via transesterification reaction with alcohol in the presence of catalyst. This paper will review briefly (1) the effect of reaction conditions such as catalyst type, amount of free fatty acid and moisture, molar ratio of alcohol and oil, alcohol type, reaction temperature and time and stirring intesity, (2) downstream process of biodiesel after transesterification reaction, and (3) potentialities of biodiesel as an alternative fuel based on its properties in diesel engines.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.39-49
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• 1999

Urban streams have, recently, been straightened and widened to alleviate flooding problem. As a result, the stream have been modified inadvertently for ecological functions and microtopography. In this study, we investigated riparian vegetation and microtopography of the tributaries of Han River before and after the monsoon rain in summer. The purpose of this study was to relate the stream microtopography to the distribution of riparian vegetation. The stream microtopography was investigated for its scale and pattern. Vegetation was investigated from 131 plots by Braun-Blanquet method. The distribution of riparian vegetation was significantly correlated with the stream microtopography. Various herbaceous species occurred at stream bank slop, high terrace and channel side. However, at channel side and concave part of terrace where soils were in high moisture level, only a few wetland species were dominated. The complexity of the microtopography in the stream corridors led to heterogeneous riparian vegetation. The vegetation showed more stability against flooding at the stream corridors with natural and complex microtopography than at the urban-type stream corridors with simple topographical features. The results showed that the development of riparian vegetation was influenced by the changes in microtopography, which was primarily determined by the shape and characteristics of channel. It seemed that a close-to-nature river system would be restored more readily with an understanding of microtopographical features affecting the distribution of riparian vegetation.

• Journal of Environmental Science International
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• v.25 no.12
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• pp.1597-1611
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• 2016

A numerical assessment using mesoscale-CFD (computational fluid dynamics) coupled A2C (atmosphere to CFD) model was carried out to analyze the variation of microscopic air flow pattern due to the construction of the Chilgok barrage in the Nakdong River. Scenarios with air flow patterns were classified into pre- and post-construction. The increased width of the river due to the construction of the Chilgok barrage induced obvious changes in moisture and the thermal environment around the river. However, air temperature variation was restricted within an area along the windward side in the numerical assessment. The impact of barrage construction on air temperature tends to be stronger during the nighttime than the daytime. It also stronger during the winter than the summer. In the simulation, the convergence of mesoscale wind is more pronounced after barrage construction than before. This is caused by the change of heat flux pattern induced by the widening of the river. Although this work is a case study with restricted atmospheric stability conditions that has several limitations in the numerical simulations, the impacts of the land-use changes brought about by the construction of the barrage in the river acceptable.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.135-141
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• 2017

This study was carried out to investigate physical properties of chicken emulsion sausage containing various amount of buckwheat powder. The fat content and apparent viscosity were observed gradually raised with level of buckwheat powder. The buckwheat powder contents influenced to improvement of emulsion stability. Increasing of buckwheat powder contents induced statistically decreasing of cooking loss and increasing of moisture contents of cooked sausage. However, hardness of cooked sausage was increased with level of buckwheat powder, it was due to gelatinization between protein and starch. In this study, it was suggested that addition of buckwheat powder contained higher dietary fiber changed physical properties of meat products.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.36-50
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• 2009

To suggest the native plants combination for restoration of the dissected sloping area, the plant communities of thirty seven quadrats from five localities of mid-southern part of Korean peninsula were surveyed from 2007 to 2008. Their flora, vegetation structure, and dominant species based on the importance value were investigated. And the soil characters (pH, moisture content, water holding capacity, and organic matter) of each dominant species were analyzed. Also, germination tests were performed to check the stability of restored native plants using seed chips. As a result, 79 native plants were suggested for the dissected sloping area : 20 trees and subtrees for the upper layer, 18 shrubs and vines for the middle layer, and 41 herbs for the lower layer, taken together their flora, dominant species, vegetation structure, soil condition, germination test, flowering period.

• Journal of the Korean Wood Science and Technology
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• v.24 no.3
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• pp.101-109
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• 1996

Effects of process variables were evaluated in physical properties of the wood fiber-thermoplastic fiber composites using nonwoven web method. Turbulent air mixer using compressed air was employed to mix wood fiber with two types of thermoplastic polypropylene and nylon 6 fibers. The optimal hot press temperature and time were found to be $190^{\circ}C$ and 9 minutes in wood fiber-polypropylene fiber composite and to be $220^{\circ}C$ and 9 minutes in wood fiber-nylon 6 fiber composite. As the density of wood fiber-polypropylene fiber composite and wood fiber-nylon 6 fiber composite increased, the physical properties were improved The density appeared to be the most significant factor on physical properties in the statistical analysis. The composition ratio of polypropylene or nylon 6 fiber to wood fiber was considered not to be statistically significant factor. The thickness swelling decreased somewhat in wood fiber-polypropylene fiber composite and wood fiber-nylon 6 fiber composite as the content of synthetic fiber increased. As the increase of mat moisture content, dimensional stability was improved in wood fiber-polypropylene fiber composite but not in wood fiber-nylon 6 fiber composite.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.539-550
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• 2016

The objective of this research was to evaluate physical and mechanical properties of three species of Styrax woods from North Tapanuli in Indonesia. The woods were more than 15 years old. Physical properties such as specific gravity, green moisture content, and volume shrinkage were determined by the procedures based on BS-373 standard for small clear specimen. Furthermore, mechanical properties, including modulus of rupture, modulus of elasticity, compression parallel to grain and hardness were also tested according to the standard. Along the stem direction, the edge section had better properties compared with those near the pith section. And the base section had also better properties than upper section. Based on the specific gravity, all of the Styrax woods in this research were classified into III-IV strength classes. A good dimensional stability was demonstrated by the value of the tangential and radial ratio which reached one. With the consideration of the mechanical properties, Styrax woods were suitable use for raw materials of light construction, furniture and handy craft.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2000.11a
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• pp.471-482
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• 2000

A special double drier structure at a plant level is developed to recycle old ascon as well as an economic mixture rate of old with new is analyzed under safety consideration in this thesis. Based upon the experimentations performed throughout this research, 35% of old ascon mixture is found to be the best for flow test, stability, air void, density, and moisture susceptibility. It is also found that the mixture does not meet the requirement in indirect tensile test, However, it is concluded that it is not critical at all since the experimental results present that the difference is too small to give any meaningful indication. A good return for the investment of this facility can be obtained if the mixture rate guideline suggested in this research is kept.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.181-186
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• 2000

This study was designed to investigate the preparation of canned pufferfish and its quality during storage at 4$^{\circ}C$${\pm}$0.5 and 25$^{\circ}C$${\pm}$0.5. The proximate compositions of the raw pufferfish were moisture 77.8%, protein 18.4% and lipid 3.3%. After the preparation of canned pufferfish there were no significant changes. During storage at 4$^{\circ}C$${\pm}$0.5 and 25${\pm}$0.5, the amino nitrogen(NH2-N) contents and acid value(AV) in both the raw and canned pufferfish revealed little difference. The volatile basic nitrogen(VBN) contents in the raw and canned pufferfish were in the range of 10.7mg/100g∼19.2mg/100g, and had no change during storage. Viable cell counts of the canned pufferfish had no change during storage at 4$^{\circ}C$${\pm}$0.5 and 25$^{\circ}C$${\pm}$0.5. The toxicity was below 2MU/g in the raw pufferfish, and it was also nontoxic in the canned pufferfish during storage.

• Korean journal of food and cookery science
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• v.7 no.4
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• pp.51-61
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• 1991

Physical and chemical properties of glycosylsucrose were characterized as follows: 1. The moisture content of glycosylsucrose syrup (35% , w/w) was 63.6% and total sugar in solid was 35.9%. 2. Main sugar compositions of glycosylsucrose syrup were maltotetraose 54.5%, sucrose 18.0%, glycosylsucrose 15.3%, maltosylsucrose 11.3% and the content of glucose, maltose, maltotriose and fructose were very little. 3. Perceived sweetness threshold of glycosylsucrose was 0.71%, relative sweetness was 0.53, and sweetness intensity expressed as power function was S=$0.78^{\circ}$C^{1.5}$$. 4. Viscosity of glycosylsucrose was higher than that of sucrose and Japanese product at 10, 25, 35 and $65^{\circ}C$. 5. The content of water absorption of gylcosylsucrose at Aw 0.80 was 0.48 g $H_2$O/g dry weight while that of sucrose was 0.17g $H_2$O/g dryweight at Aw 0.86. 6. The stability of glycosylsucrose was decreased by acidic pH, high temperature and long heating time. 7. The glycosylsucrose showed very little browning when heated with pepton, but alkaline pH (pH8), high temperature and long heating time increased browning reaction.